MCP `app_deploy` refuses in the deploys page's words, not `refused: <code>` #7607

app_deploy now refuses stop and redeploy in the deploys page's words instead of refused: <code>. The error codes are unchanged. tsc is clean, and test/mcp-app-deploy.test.ts and test/mcp-size.test.ts pass.

• Shared words: src/actions/env_words.ts already held one sentence per error that stopEnv and redeployEnv can return. The web page and the terminal deploys screen already read from it, so I added no new module and made no page edits.
• The change: src/http/mcp/tools/app_deploy.ts now calls envRefusalText for both actions.
• New test: it covers a non-admin and an unknown environment. For both, it asserts the code is kept and the page's sentence appears in the message. It also covers a missing repository, which the MCP answers with its generic "no such app or repository" message. not_found itself cannot be reached over the MCP for an existing repository, so the test only checks that the page's sentence for it exists.

I did not touch the other tools' messages.

Closes #7597